Biostatistical expertise was provided to researchers from NCI and other institutions on the design and statistical analysis of a broad range of laboratory studies including: host cell reactivation studies in the Dermatology Branch, DCS, NCI to examine the functional impact of defective nucleotide excision repair of specific lesions induced by oxygen radicals in mutant Chinese Hamster Ovary cells and in cells from patients with xeroderma pigmentosum; a study of the survival of knockout mice with the Veterinary and Tumor Pathology Section; a study of DNA-adduct measurements in mothers treated for HIV infection with AZT and in the placentas of their babies by the Laboratory of Chemical Carcinogenesis and Tumor Promotion; an investigation of polymorphic variation in the XPC gene by the Laboratory of Molecular Carcinogenesis and the possible association of a recently identified marker allele with cancer risk; experiments in the Laboratory of Molecular Biology comparing tumor rates and cell division rates in transgenic and wild type mice; a study of variation in cancer risk for a particular genetic polymorphism with the Yale University Department of Therapeutic Radiology and Genetics; a study with the University of Texas Southwestern Medical Center of molecular changes in lung cancers and breast cancers following treatment for Hodgkins disease; an investigation in the Laboratory of Human Carcinogenesis and at the University of Vermont examining evolutionary conservation of p53 and p16 mutational hot spots found in human cancers; a study of the fetal effects of alcohol in knockout mice with the Laboratory of Neurogenetics of the NIAAA; an investigation in the Laboratory of Molecular Genetics of the NIA evaluating excesses of clustered mutations in immunoglobulin genes of PMS2 and MSH2 knockout mice; a study by the Laboratory of Molecular Genetics of the NIA measuring repair of oxidative DNA damage in patients with primary neurologic degenerations; a study by the University of Minnesota Laboratory of Environmental Medicine and Pathology of chromosome damage and hormone levels in pesticide appliers.